body, html {
    margin: 0;
    padding: 0;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: #f0f0f0;
    color: #333;
}
/* 添加导航栏的样式 */
.navbar {
    background-color: #21252b;
    color: #abb2bf;
    padding: 0.5rem 1rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 1000;
    font-family: 'Source Code Pro', monospace;
}

.nav-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    width: 100%;
}

.nav-logo {
    font-weight: bold;
    color: #e06c75;
    text-decoration: none;
    font-size: 24px;
}

.nav-menu {
    display: flex;
    list-style: none;
}

.nav-item {
    margin: 0 1rem;
}

.nav-link {
    color: #abb2bf;
    text-decoration: none;
    padding: 0.5rem 1rem;
    border-radius: 5px;
    transition: background-color 0.3s ease;
}

.nav-link:hover {
    background-color: #56b6c2;
    color: white;
}
.oj-app {
    max-width: 1200px;
    margin: 40px auto;
    padding: 20px;
    background-color: #fff;
    border-radius: 8px;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease-in-out;
}

.oj-app:hover {
    transform: translateY(-5px);
}

.oj-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
}

.oj-header h1 {
    color: #007bff;
    font-size: 2em;
    margin: 0;
}

.logo {
    color: #ff6347; /* Tomato */
}

.oj-nav ul {
    list-style: none;
    padding: 0;
    display: flex;
}

.oj-nav ul li {
    margin-left: 20px;
}

.oj-nav ul li .nav-link {
    text-decoration: none;
    color: #007bff;
    font-weight: bold;
    padding: 5px 10px;
    border-radius: 5px;
    transition: background-color 0.3s ease-in-out;
}

.oj-nav ul li .nav-link:hover {
    background-color: #007bff;
    color: #fff;
}

.oj-problems ul {
    list-style: none;
    padding: 0;
}

.oj-problem {
    margin-bottom: 20px;
    padding: 15px;
    border-radius: 5px;
    background-color: #e9ecef;
    transition: background-color 0.3s ease-in-out;
    cursor: pointer;
}

.oj-problem:hover {
    background-color: #dde2e6;
}

.oj-problem h3 {
    margin: 0;
    color: #007bff;
}

.oj-problem p {
    margin: 5px 0;
    color: #495057;
}